CN220232837U

CN220232837U - Multilayer PPTC element

Info

Publication number: CN220232837U
Application number: CN202321689740.1U
Authority: CN
Inventors: 王勇
Original assignee: Jiaxing Keruite Electronic Materials Co ltd
Current assignee: Jiaxing Keruite Electronic Materials Co ltd
Priority date: 2023-06-12
Filing date: 2023-06-30
Publication date: 2023-12-22
Anticipated expiration: 2033-06-30

Abstract

The utility model discloses a multilayer PPTC element, and belongs to the technical field of thermistors. The multi-layer PPTC element includes a host structure and an electrode structure. The main body structure is made on the basis of a plurality of composite units, wherein a plurality of PPTC core materials are arranged in parallel, and the main body structure is provided with two electrode connecting surfaces or surface groups. The electrode structure comprises two electrode members respectively arranged on a first electrode connection surface or surface group and a second electrode connection surface or surface group, and the two electrode members are used as electrodes for connecting the multi-layer PPTC element with an external member. Different types of electrode structures and different relationships between electrode structures and body structures may form different types of PPTC elements, such as plug-in PPTC elements, terminating PPTC elements, and ribbon PPTC elements. The multi-layer PPTC element provided by the utility model can realize the breakthrough of producing multi-layer plug-in type, multi-layer terminal type and multi-layer strip-shaped PPTC elements, and has the advantages of simple production steps and high production efficiency.

Description

Multilayer PPTC element

Technical Field

The utility model relates to the technical field of thermistors, in particular to a multilayer PPTC element.

Background

PPTC elements, i.e., polymeric positive temperature coefficient thermistors, also known as self-healing fuses, can be used as overcurrent protection elements. The PPTC element comprises a PPTC substrate and electrode plates or leads welded on the PPTC substrate, wherein the PPTC substrate is provided with a PPTC core material and metal foils arranged on two surfaces of the PPTC core material. The PPTC core material is a high-molecular composite material obtained by filling conductive particles in a high-molecular polymer and further processing. The principle of operation of PPTC elements is an energy balance, when overcurrent flows through the PPTC core material, heat is generated due to the relationship of joule law, and part of the generated heat energy is emitted to the environment, and the temperature of the element is increased due to the part of the heat energy which is not emitted.

After the PPTC element is applied to a circuit, under normal working conditions, the high-molecular polymer and the conductive particle material are combined together in high density to form a crystalline structure, and the PPTC core material shows extremely low resistance value and basically does not influence the circuit performance; when abnormal current (such as overcurrent) occurs or the ambient temperature is increased, the high molecular polymer in the PPTC core material thermally expands due to spontaneous heat caused by Joule heat, the inter-particle distance of conductive particles in the PPTC core material expands, the conductive particle bonds start to break, and a conductive path is interrupted; when the circuit is removed or cut off by fault, self-heating stops, the PPTC core material is thermally contracted, the distance between conductive particles is shortened, and the conductive path is reformed, so that the circuit can return to a normal working state.

Referring to fig. 1, in the process for producing the PPTC device, raw materials are weighed according to a ratio, and then are subjected to material refining, granulation and molding to obtain a PPTC core material 100, and the PPTC core material 100, the first conductive layer 200 and the second conductive layer 300 are compounded to obtain a composite board, which is equivalent to a collection of a plurality of PPTC substrates. The subsequent processing steps are different according to the types of PPTC elements to be manufactured, and for the plug-in type, terminal type and strip-shaped PPTC elements, appropriate electrode plates or leads are selected, and the electrode plates are welded on the first conductive layer 200 and the second conductive layer 300 respectively, and then the plug-in type and the strip-shaped PPTC elements can be encapsulated.

However, in the prior art, the plug-in type, terminal type and ribbon-shaped PPTC elements on the market have only a single layer structure, and cannot produce a multi-layer structure product.

Disclosure of Invention

One of the purposes of the present application is to provide a multi-layer PPTC element which can be used for producing plug-in, strip-type and termination-type products, and which solves the problem that the prior art cannot produce multi-layer plug-in, multi-layer termination-type and multi-layer strip-type PPTC products.

In order to achieve the above object, the present utility model provides the following technical solutions.

A multi-layer PPTC element fabricated on the basis of a plurality of composite units; the composite unit comprises a PPTC core material and electrode layers arranged on two surfaces of the PPTC core material, and when the electrode layers extend out of the PPTC core material, the extending part is an extension electrode;

the multi-layer PPTC element is provided with two electrode connection surfaces or surface groups, namely a first electrode connection surface or surface group positioned on a first surface or surface group and a second electrode connection surface or surface group positioned on a second surface;

after each composite unit is arranged in a stacking mode, a first side and a second side of the multi-layer PPTC element are respectively provided with at least one epitaxial electrode, wherein the first side and the second side are oppositely arranged;

The epitaxial electrode is bent and causes: one electrode layer in each composite unit is electrically connected with each other and forms the first electrode connection surface or surface group, or can be electrically connected with the first electrode connection surface or surface group through an electric conductor, and the other electrode layer in each composite unit is electrically connected with each other and forms the second electrode connection surface or surface group, or can be electrically connected with the second electrode connection surface or surface group through an electric conductor;

when the epitaxial electrode is bent, the electrode layer corresponding to the first electrode connection surface or the surface group is electrically isolated from the electrode layer corresponding to the second electrode connection surface or the surface group.

Optionally, two electrode layers between adjacent PPTC core materials are welded and electrically connected, or bonded and electrically isolated by an insulating material.

Optionally, at least part of the sides of the PPTC core material are provided with an insulating material to be electrically isolated from the bent epitaxial electrode.

Optionally, at least one of the electrode connection surfaces or surface groups is continuously arranged, and the electrode connection surfaces or surface groups that are continuously arranged are realized by any one of the following modes:

(1) The epitaxial electrode partially covers and is electrically connected with an electrode layer positioned on the outermost layer of the multi-layer PPTC element, and the part, which is positioned on the electrode layer on the outermost layer of the multi-layer PPTC element and is not covered by the epitaxial electrode, forms an electrode connection surface or a surface group;

(2) The epitaxial electrode covers and is in insulating connection with an electrode layer positioned on the outermost layer of the multi-layer PPTC element, the coverage area of the epitaxial electrode extends from the first side to the second side, and an electrode connection surface or a surface group is formed on the surface of the coverage area.

Optionally, at least one of the electrode connection faces or face groups includes a first region and a second region that are intermittently disposed, where the electrode connection face or face group is implemented by any one of the following means:

(1) The first area is formed by an electrode layer which is positioned on the outermost layer of the multi-layer PPTC element and is compounded on the PPTC core material, and the second area is formed by bending an epitaxial electrode to be flush with the electrode layer;

(2) The first region is formed by an electrode layer which is positioned on the outermost layer of the multi-layer PPTC element and is compounded on the PPTC core material, the part of the epitaxial electrode which is covered on the electrode layer is a covering part, and the second region is the surface of the covering part.

Optionally, the multi-layer PPTC element is made by a plurality of second composite units, or is made by a first composite unit and a third composite unit together, or is made by a second composite unit and a third composite unit together, or is made by a first composite unit, a second composite unit and a third composite unit together;

In the first composite unit, two electrode layers are respectively provided with one epitaxial electrode, and the two epitaxial electrodes are positioned on opposite sides of the PPTC core material; the second composite unit has only one of the epitaxial electrodes; in the third composite unit, the peripheral edges of the two electrode layers do not extend out of the PPTC core material.

Optionally, the number of the composite units is two, and the second composite units are adopted, wherein:

the electrode layer with the epitaxial electrode is adhered between two PPTC core materials through an insulating material, wherein one epitaxial electrode and the electrode layer at the first surface or the surface group jointly correspond to the first electrode connecting surface or the surface group, and the other epitaxial electrode and the electrode layer at the second surface jointly correspond to the second electrode connecting surface or the surface group; or,

after lamination, two electrode layers with epitaxial electrodes are respectively positioned between the second surface and the two PPTC core materials, wherein the epitaxial electrodes positioned on the second surface and the electrode layers positioned on the first surface or the surface group correspond to the first electrode connecting surface or the surface group together, and the epitaxial electrodes positioned between the two PPTC core materials are bent to the second surface and extend from the first side to the second side.

Optionally, the number of the compound units is three, one of the compound units is the first compound unit, and the other two compound units are the third compound unit, wherein:

the first composite units are arranged between the two third composite units, electrode layers between adjacent PPTC core materials are welded and fixed, one epitaxial electrode is bent to partially cover the electrode layer positioned on the first face or the face group and is electrically connected with the electrode layer, and the other epitaxial electrode is bent to partially cover the electrode layer positioned on the second face and is electrically connected with the electrode layer.

Optionally, from the first surface or the surface group to the second surface, the composite units respectively adopt a second composite unit, a first composite unit, a second composite unit and a second composite unit; electrode layers between adjacent PPTC core materials are welded and fixed;

and the other epitaxial electrode is bent from a position close to one end of the multi-layer PPTC element and partially covers the electrode layer positioned at the other end of the multi-layer PPTC element.

Optionally, the multilayer PPTC element further comprises a first electrode member and a second electrode member;

The first electrode component is fixed on the first electrode connecting surface or the surface group and forms an electric connection relation with the electrode layer corresponding to the first electrode connecting surface or the surface group;

the second electrode member is secured to the second electrode connection face or face set and is in electrical connection with the electrode layer corresponding to the second electrode connection face or face set.

Optionally, the first electrode member and the second electrode member are respectively sheet-shaped, and a periphery of the first electrode member and a periphery of the second electrode member do not protrude from a side surface of the multi-layer PPTC element.

Optionally, one side of the first electrode member protrudes with respect to each of the PPTC core materials to form a first protruding portion, and one side of the second electrode member protrudes with respect to each of the PPTC core materials to form a second protruding portion.

Optionally, the first electrode member and the second electrode member employ leads, and the first protruding portion and the second protruding portion are located on the same side.

Optionally, the first electrode member and the second electrode member adopt electrode plates, and the first protruding portion and the second protruding portion are located on opposite sides.

Optionally, an encapsulation structure is wrapped on the surface of the multi-layer PPTC element, and the first protruding portion and the second protruding portion protrude from the encapsulation structure.

Optionally, each PPTC core material has the same thickness, or at least one PPTC core material has a thickness different from that of other PPTC core materials;

each of the PPTC cores may be of the same known material or at least one PPTC core may be of a different known material than the other PPTC cores.

The utility model at least has the following beneficial effects:

1. the multi-layer PPTC element is made of composite units, after the composite units are stacked, the first side and the second side are provided with epitaxial electrodes, the epitaxial electrodes are processed, so that the PPTC core materials are connected in parallel, a first electrode connection surface or surface group and a second electrode connection surface or surface group are formed, the two electrode connection surfaces or surface groups can be matched with a lead electrode and a sheet electrode to form the multi-layer plug-in type PPTC element, the multi-layer terminal type PPTC element and the multi-layer strip-shaped PPTC element, and the breakthrough of producing the multi-layer plug-in type PPTC element, the multi-layer terminal type PPTC element and the multi-layer strip-shaped PPTC element is structurally realized.

2. In the prior art, the production processes and production equipment of plug-in type PPTC elements, terminal type PPTC elements and strip-shaped PPTC elements are based on PPTC substrates, the PPTC substrates are always in a form of flush sides due to mature production processes and production lines, the improved PPTC substrates relate to process adjustment and production line adjustment generated by the process adjustment, people are habitually produced according to the prior art, and the production processes, the production lines and the inertia thinking of people are limited, and no one has proposed to produce a multilayer structure by deforming the PPTC substrates; the utility model is based on a composite unit, at least two epitaxial electrodes are arranged in a plurality of composite units, and the parallel connection between PPTC core materials 1 is realized by bending the epitaxial electrodes and setting the relation between electrode layers, wherein the process for compositing the composite units with the epitaxial electrodes is different from the prior art, and each process involved in the lamination placement of each composite unit and the process for connecting each composite unit are also different from the prior art, in other words, the utility model breaks through the limitation of the traditional production process and breaks through the inertia thinking.

3. The utility model is a great commercial breakthrough. The multi-layer plug-in type PPTC element, the multi-layer terminal type PPTC element and the multi-layer strip type PPTC element which are generated by the composite unit can be widely applied to battery industry, telecommunication and industrial equipment, automobile electronics and new energy automobiles, electronic industry, intelligent small household appliances, security equipment and computer equipment, so that the multi-layer plug-in type PPTC element and the multi-layer strip type PPTC element have huge commercial value.

Drawings

The technical features and advantages of the present utility model may be more fully understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic structural diagram of a conventional PPTC substrate.

Fig. 2 is a schematic structural diagram of a first composite unit according to embodiment 1 of the present utility model.

Fig. 3 is a schematic structural diagram of a second composite unit according to embodiment 2 of the present utility model.

Fig. 4 is a schematic structural diagram of a third composite unit according to embodiment 3 of the present utility model.

Fig. 5 is a schematic structural diagram of a dual-layer PPTC device of embodiment 4 of the present utility model.

Fig. 6 is a schematic structural diagram of a dual layer PPTC device according to an embodiment of the present utility model.

Fig. 7 is a schematic structural diagram of a dual layer PPTC device of embodiment 5 of the present utility model.

Fig. 8 is a schematic structural diagram of a dual layer PPTC device according to an embodiment of the present utility model.

Fig. 9 is a schematic structural diagram of a dual layer PPTC device of embodiment 6 of the present utility model.

Fig. 10 is a schematic structural diagram of a dual-layer PPTC device of embodiment 7 of the present utility model.

Fig. 11 is a schematic structural diagram of a dual-layer PPTC device of embodiment 8 of the present utility model.

Fig. 12 is a schematic structural diagram of a dual layer PPTC device according to an embodiment of the present utility model.

Fig. 13 is a schematic structural diagram of a dual layer PPTC device according to an embodiment of the present utility model.

Fig. 14 is a schematic structural diagram of a dual layer PPTC device according to an embodiment of the present utility model.

Fig. 15 is a schematic structural diagram of a three-layer PPTC device of embodiment 9 of the present utility model.

Fig. 16 is a schematic structural diagram of a three-layer PPTC device of embodiment 9 of the present utility model.

Fig. 17 is a schematic structural diagram of a three-layer PPTC device according to an embodiment of the present utility model.

Fig. 18 is a schematic structural diagram of a three-layer PPTC device according to an embodiment of the present utility model.

Fig. 19 is a schematic structural diagram of a three-layer PPTC device of embodiment 10 of the present utility model.

Fig. 20 is a schematic structural diagram of a five-layer PPTC element of example 11 of the present utility model.

Fig. 21 is a schematic structural diagram of a five-layer PPTC element of example 11 of the present utility model.

Fig. 22 is a schematic structural diagram of a five-layer PPTC device according to an embodiment of the present utility model.

Fig. 23 is a schematic structural diagram of a five-layer PPTC device according to an embodiment of the present utility model.

Fig. 24 is a schematic structural diagram of a five-layer PPTC element of example 12 of the present utility model.

Fig. 25 is a schematic structural diagram of a dual-layer PPTC device according to an embodiment of the present utility model.

Reference numerals:

the utility model comprises the following steps:

10. a first composite unit; 20. a second composite unit; 30. a third composite unit;

1. a PPTC core material; 11. a first surface; 12. a second surface; 13. a first side; 14. second side surface

2. A first electrode layer; 21. a first composite section; 22. a first epitaxial electrode;

3. a second electrode layer; 31. a second composite section; 33. a second epitaxial electrode;

41. a first electrode connection face or set of faces; 42. a second electrode connection face or set of faces; 43. a first region; 44. a second region;

51. a first face or set of faces; 52. a second face; 53. a first side; 54. a second side;

61. a first insulating portion; 62. a second insulating portion; 63. a third insulating portion;

71. a first electrode member; 72. a second electrode member; 73. a first protruding portion; 74. a second protruding portion;

8. an encapsulation structure;

9. solder paste;

the prior art comprises the following steps:

100. a PPTC core material; 200. a first conductive layer; 300. and a second conductive layer.

Detailed Description

Unless defined otherwise, technical or scientific terms used in the specification and claims should be given the ordinary meaning as understood by one of ordinary skill in the art to which the utility model pertains.

The terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

The welding technology related in the following description adopts the first positioning by spot-plating the solder paste, and after all the solder paste positioning is completed, the solder paste is melted to realize welding fixation, and the welding position is represented by the solder paste in the drawing; considering that solder paste is a mature technology in the prior art, and the solder paste is not an important point of the utility model, the positions with solder paste at all points are uniformly marked in the following description, and different marks are not arranged on each solder paste.

The multi-layer PPTC element provided by the embodiment of the present utility model is manufactured on the basis of a composite unit, and the composite unit and the multi-layer PPTC element are described in the following, on the basis of which a method for manufacturing a PPTC core material, a method for manufacturing a composite unit, and a method for manufacturing a multi-layer PPTC element are described, and then the composite unit and the multi-layer PPTC element are illustrated by several embodiments in conjunction with fig. 2 to 24.

As will be understood with reference to fig. 2 to 4. The embodiment of the utility model provides a composite unit which comprises a PPTC core material 1 and electrode layers arranged on two surfaces of the PPTC core material 1, wherein when the electrode layers extend out of the PPTC core material 1, the extending part is an extension electrode. The PPTC core material 1 may be in a sheet shape, and the two surfaces thereof are a first surface 11 and a second surface 12, and the electrode layer includes a first electrode layer 2 connected to the first surface 11 and a second electrode layer 3 connected to the second surface 12.

Each electrode layer has a composite portion for connection with the PPTC core material 1, for example, the first electrode layer 2 has a first composite portion 21, the second electrode layer 3 has a second composite portion 31, the first composite portion 21 and the second composite portion 31 are respectively bonded to the PPTC core material 1, and in some embodiments, the PPTC core material 1, the first composite portion 21 and the second composite portion 31 are compositely formed, and the compositely forming process may be performed by using the prior art, for example, hot press forming.

In some embodiments, the thickness of the electrode layer is within 8.0 μm to 100 μm, such as 8.0 μm, 45 μm, or 100 μm. The volume resistivity of the electrode layer is lower than 10 mu omega cm. One surface of the electrode layer, which is attached to the PPTC core material 1, is roughened to improve the bonding force of the electrode layer and the PPTC core material 1. The electrode layer has a nickel plating layer on its roughened surface or both surfaces. The electrode layer may be an electrode foil, the base material of the electrode foil is a metal or metal alloy, and preferably the electrode layer is one of an electrolytic copper foil and a rolled copper foil.

When the relationship between the electrode layer and the PPTC core material 1 is different, the types of the composite units are different. The first recombination unit 10 and the second recombination unit 20 both have epitaxial electrodes, and the third recombination unit 30 has no epitaxial electrode. As shown in fig. 2, in the first composite unit 10, two of the electrode layers each have one of the epitaxial electrodes, and the two epitaxial electrodes are located on opposite sides of the PPTC core material 1, i.e., the first electrode layer 2 has a first epitaxial electrode 22 protruding with respect to a first side 13 of the PPTC core material 1, and the second electrode layer 3 has a second epitaxial electrode 32 protruding with respect to a second side 14 of the PPTC core material 1, the first side 13 and the second side 14 being disposed opposite. As shown in fig. 3, only one epitaxial electrode is provided in the second composite unit 20, and the other peripheral edges of both electrode layers do not protrude from the PPTC core material 1. As shown in fig. 4, the third composite unit 30 is not provided with an epitaxial electrode, i.e. the peripheral edges of both electrode layers do not protrude from the PPTC core material 1, and of course, the third composite unit 30 can also be interpreted as the prior art (i.e. PPTC substrate) shown in fig. 1.

The epitaxial electrode can be formed in the process of compounding the first electrode layer 2, the second electrode layer 3 and the PPTC core material 1, namely, the first electrode layer 2 and/or the second electrode layer 3 extend out of the PPTC core material 1 for a certain length according to design requirements during compounding; of course, the third composite unit 30 is prepared without extending the electrode layer beyond the PPTC core material 1.

In a production process, a long product is formed after the PPTC core material 1, the first electrode layer 2 and the second electrode layer 3 are compounded, the product is equivalent to a collection of a plurality of PPTC core materials 1, and a part for forming an epitaxial electrode is reserved or an epitaxial electrode is not reserved in the width direction of the product according to requirements, so that a compound unit is obtained.

In the application of the composite unit, the epitaxial electrode may be processed (e.g., bent, welded after folding, cut or otherwise manipulated) and then used as an electrode for connecting components outside the composite unit. The composite unit can be used for manufacturing various types of PPTC elements, and the application of the composite unit in the multi-layer PPTC element is mainly described, especially in the multi-layer plug-in type PPTC element, the multi-layer terminal type PPTC element and the multi-layer strip-shaped PPTC element.

The multi-layer PPTC element includes a host structure and an electrode structure. The PPTC cores 1 of the main structure are arranged in parallel, the main structure has two electrode connection faces or face groups, namely a first electrode connection face or face group 41 on one face of the main structure and a second electrode connection face or face group 42 on the other face of the main structure (the first electrode connection face or face group 41 is located on a first face or face group 51 of the multi-layer PPTC element and the second electrode connection face or face group 42 is located on a second face 52 of the multi-layer PPTC element). The electrode structure comprises two electrode members mounted on a first electrode connection face or face set 41 and a second electrode connection face or face set 42, respectively, such that the PPTC core material 1 after being connected in parallel has a pair of electrodes for connection to an external member such as a circuit board. Different types of electrode structures and different relationships between the electrode structures and the main body structures can form different types of PPTC elements (such as plug-in type PPTC elements, terminal type PPTC elements and strip-shaped PPTC elements).

It should be noted that, the electrode connection surface or surface group is defined as a surface group formed by a single surface or multiple surfaces connected with the electrode structure on the main structure, and comparing fig. 6 and fig. 25, it is understood that in fig. 6, the first electrode member 71 is attached to the second electrode layer 3 above, and the attached area is the electrode connection surface or surface group, where the electrode connection surface adopts a single surface that is continuously arranged; as shown in fig. 25, the first electrode member 71 is attached and connected to the second electrode layer 3 above and the surface of the covering portion folded onto the second electrode layer 3 at the same time, and at this time, a part of the electrode connection surface is located on the second electrode layer 3 and the other part is located on the covering portion; as shown in fig. 6 and 25, the two multilayered PPTC elements have two configurations in which the main structure is identical, but the electrode connection surfaces are different, and the connection positions between the main structure and the electrode structure are different.

The main structure may be interpreted differently in terms of construction. The first explanation is that the main structure includes a plurality of PPTC core materials 1 and electrode layers arranged at intervals, wherein a part of the electrode layers can establish an electrical connection relationship and form a first electrode connection surface or surface group 41, and another part of the electrode layers can establish an electrical connection relationship and form a second electrode connection surface or surface group 42; the electrode layers are divided into two types, wherein the periphery of one type of electrode layer does not extend out of the periphery of the PPTC core material 1, the other type of electrode layer is provided with an extension electrode which extends out of the PPTC core material 1, and the electrode layers are directly or indirectly electrically connected through bending the extension electrode. The second explanation describes the main structure on the basis of the composite unit, and considering that the inventive concept and improvement of the technology are based on the composite unit, the present utility model mainly adopts the second explanation to describe the multi-layer PPTC element and the preparation method thereof.

Specifically, the main structure is made on the basis of a plurality of composite units, after each composite unit is stacked, a first side 53 and a second side 54 of the multi-layer PPTC element are respectively provided with at least one epitaxial electrode, and the first side 53 and the second side 54 are oppositely arranged. Of course, the epitaxial electrodes of the first side 53 and the epitaxial electrodes of the second side 54 correspond to different electrode connection faces or sets of faces, respectively. The epitaxial electrode is bent such that: one electrode layer of each of the composite units is electrically connected to each other and forms the above-described first electrode connection face or face group 41, or can be electrically connected by an electric conductor at the first electrode connection face or face group 41, and the other electrode layer of each of the composite units is electrically connected to each other and forms the second electrode connection face or face group 42, or can be electrically connected by an electric conductor at the second electrode connection face or face group 42. The epitaxial electrodes are provided with an insulating material to electrically isolate the electrode layer corresponding to the first electrode connection face or face set 41 from the electrode layer corresponding to the second electrode connection face or face set 42.

In the main structure, there are various connection modes between two adjacent composite units, such as bonding, fixing and welding and fixing by insulating materials, and the main difference between the two fixing modes is that two electrode layers between two adjacent PPTC core materials 1 are in insulating connection or conductive connection, and for convenience of description, the two electrode layers are respectively defined as a first connection layer and a second connection layer.

In the bonding and fixing manner, a first insulating portion 61 (as shown in fig. 5 to 10) made of an insulating material is disposed between the first connecting layer and the second connecting layer to perform insulation and isolation, the first insulating portion 61 is bonded and fixed with the first connecting layer and the second connecting layer respectively, and an electrode connection surface or a surface group corresponding to the first connecting layer is different from an electrode connection surface or a surface group corresponding to the second connecting layer.

In the welding and fixing mode, the first connecting layer and the second connecting layer are mutually attached, and the first connecting layer and the second connecting layer are welded and fixed (solder paste 98 is firstly dispensed between the first connecting layer and the second connecting layer, and then fixation is realized through reflow soldering), and the first connecting layer and the second connecting layer correspond to the same electrode connecting surface or surface group.

In a specific embodiment, all adjacent composite units can be connected in an adhesive fixing manner, all adjacent composite units can be connected in a welding fixing manner, and part of adjacent composite units can be adhered and fixed, and other adjacent composite units can be welded and fixed, so long as parallel connection of the PPTC core materials 1 can be realized.

In the main structure, at least part of the lateral surface of the PPTC core material 1 is provided with a second insulating portion 62 (for example, fig. 5 to 24) made of an insulating material, and the second insulating portion 62 electrically isolates the PPTC core material 1 where it is located from an adjacent epitaxial electrode. When the electrode layers between the adjacent PPTC cores 1 are connected by the first insulating portion 61, the first insulating portion 61 may be integrally connected with the second insulating portions 62 located at both ends thereof.

The main structure may further have a third insulating portion 63, and when the epitaxial electrode is continuously bent to cover the electrode layer located at the outermost layer and corresponds to a different electrode connection surface or surface group with the electrode layer, the two are electrically isolated by the third insulating portion 63, as shown in fig. 11.

In the main structure, each PPTC core material 1 may have the same thickness, or the thickness of at least one PPTC core material 1 may be different from the thickness of other PPTC core materials 1. Each PPTC core material 1 may be made of the same known material, or at least one PPTC core material 1 may be made of a known material different from the other PPTC core materials 1. When the formulas and/or thicknesses of the PPTC core materials 1 in the two multi-layer PPTC elements are different, the holding currents and/or rated voltages of the two layers of PPTC elements are different, and in practical application, products with different safety levels can be obtained.

In the main body structure, the electrode connection surface or the surface group is formed by one or more electrode layers, and the electrode connection surface or the surface group can be in the form of a single continuous surface or a discontinuous surface combination formed by a plurality of surfaces, and the two modes are respectively described below.

When the electrode connection surfaces or surface groups are continuously provided, the electrode connection surfaces or surface groups to be continuously provided may be formed by any of the following means:

(1) The epitaxial electrode partially covers and is electrically connected to an electrode layer located on the outermost layer of the multi-layer PPTC element, and the portion of the electrode layer located on the outermost layer of the multi-layer PPTC element that is not covered by the epitaxial electrode forms an electrode connection surface or surface group, such as a first electrode connection surface or surface group 41 and a second electrode connection surface or surface group 42 in fig. 5, and a first electrode connection surface or surface group 41 in fig. 7 and 10.

(2) The epitaxial electrode covers and is insulated from the electrode layer located on the outermost layer of the multi-layer PPTC element, and the coverage area of the epitaxial electrode extends from the first side 53 to the second side 54, and the width of the coverage area is preferably the same as the width of the electrode layer on the outermost layer of the multi-layer PPTC element, and the surface of the coverage area forms the first electrode connecting surface or surface group 41, such as the second electrode connecting surface or surface group 42 of fig. 11.

When the electrode connection surface or the surface group is a discontinuous surface formed by a plurality of surfaces, the electrode connection surface or the surface group is formed by a plurality of electrode layers, and comprises a first area 43 and a second area 44 which are discontinuously arranged, wherein the electrode connection surface or the surface group is realized by any one of the following modes:

(1) The first region 43 is formed by an electrode layer (i.e., a composite portion of the outermost layer) that is formed by compositing the PPTC core material with the outermost layer of the multi-layer PPTC element, the second region 44 is formed by bending the epitaxial electrode to be flush with the electrode layer, and the second region 44 may be an end face of a single epitaxial electrode, as shown in fig. 7, or may be formed by jointly forming end faces of a plurality of epitaxial electrodes, as shown in fig. 21.

(2) The first region 43 is formed by an electrode layer on the PPTC core material 1, which is laminated on the outermost layer of the multilayered PPTC element, the portion of the epitaxial electrode which covers the electrode layer is a cover portion, the second region 44 is a surface of the cover portion, and the first region 43 and the second region 44 are two offset single surfaces. First, when most PPTC surface groups are very small elements, each electrode layer and PPTC core material 1 are sheet-like, and the first region 43 and the second region 44 are arranged in a staggered manner, but when connected to the electrode structure (i.e., the first electrode member 71 and the second electrode member 72), the conductive function is not affected at all, and the appearance is not affected at the same time, and the present method has advantages in terms of reliability and stability of electrical connection, and the production process is not complicated compared with other methods; of course, the requirement of having a PPTC element with a large size for some application conditions is not excluded at present and in the future, so that the thickness of the covering portion affects the product performance, the installation process or the appearance effect, and the electrode connection surface or the surface group may take forms other than this. Second, when the main structures of the two multi-layer PPTC elements are identical, the electrode connection faces may be different as shown in fig. 6 and 25, and accordingly, the two multi-layer PPTC elements are different embodiments.

In a specific embodiment, the first electrode connection surface or surface group 41 may be implemented in any of the manners described above, and likewise, the second electrode connection surface or surface group 42 may be implemented in any of the manners described above, in other words, both electrode connection surfaces or surface groups of the multi-layer PPPTC element may be implemented by a single continuous surface, as shown in fig. 5 and 11, or may be implemented by a discontinuous surface composed of multiple surfaces, as shown in fig. 10, or may be implemented by a discontinuous surface composed of a single continuous surface and multiple surfaces, as shown in fig. 9.

As described above, the complex units have three types, i.e., the first complex unit 10, the second complex unit 20, and the third complex unit 30, and accordingly, the main body structures have different types. The main structure may be manufactured by a plurality of second complex units 20 (such as fig. 5 to 14), or by a first complex unit 10 and a third complex unit 30 (such as fig. 15 to 18), or by a second complex unit 20 and a third complex unit 30 (such as fig. 19), or by a first complex unit 10, a second complex unit 20 and a third complex unit 30 (such as fig. 20 to 24).

The electrode structure includes a first electrode member 71 and a second electrode member 72; the first electrode member 71 is soldered on the first electrode connection surface or surface group 41 by solder paste, and forms an electrical connection relationship with the electrode layers corresponding to the first electrode connection surface or surface group 41, wherein when the first electrode connection surface or surface group 41 is a single continuous surface, the first electrode member 71 connects the first region 43 and the second region 44 of the first electrode connection surface or surface group 41 at the same time, so that the corresponding electrode layers form an electrical connection relationship; the second electrode member 72 is soldered to the second electrode connection surface or surface set 42 by solder paste and is in electrical connection with the electrode layers corresponding to the second electrode connection surface or surface set 42, and the second electrode member 72 connects the first region 43 and the second region 44 of the second electrode connection surface or surface set 42 at the same time so that the corresponding electrode layers are in electrical connection.

In some embodiments, the first electrode connection face or faces 41 and the second electrode connection face or faces 42 each employ a discontinuous face of a plurality of faces, the first electrode member 71 and the second electrode member 72 each being sheet-like, with the peripheral edges of the first electrode member 71 and the peripheral edges of the second electrode member 72 being aligned with the sides of the multi-layered PPTC element, thereby forming a multi-layered terminal PPTC element.

In some embodiments, a first protruding portion 73 is formed by protruding one side of the first electrode member 71 with respect to each PPTC core material 1, a second protruding portion 74 is formed by protruding one side of the second electrode member 72 with respect to each PPTC core material 1, different electrode member forms and different positional relationships between the first protruding portion 73 and the second protruding portion 74 and the PPTC core material 1 may form different products. Wherein when the first electrode member 71 and the second electrode member 72 use leads, and the first protruding portion 73 and the second protruding portion 74 are located on the same side, a multi-layer insert PPTC element is formed, and accordingly, one of the first electrode connection surface or surface group 41 and the second electrode connection surface or surface group 42 uses a continuous surface, the other uses a discontinuous surface, or both electrode connection surfaces or surface groups use discontinuous surfaces; when the first electrode member 71 and the second electrode member 72 are electrode sheets and the first protrusion 73 and the second protrusion 74 are located on opposite sides, a multi-layered strip PPTC element is formed, and accordingly, the first electrode connection face or faces 41 and the second electrode connection face or faces 42 may be two continuous faces, or two discontinuous faces, or one and continuous face, and the other discontinuous face.

The surfaces of the multi-layer insert PPTC element and the multi-layer tape PPTC element may be wrapped with an encapsulation structure 8, and the first protrusions 73 and the second protrusions 74 extend out of the encapsulation structure 8. The encapsulation structure 8 may be formed by applying an insulating coating, such as by applying an epoxy resin.

The above is an overall description of the composite unit and the multilayered PPTC element, and the PPTC core material 1, the method of producing the composite unit, and the method of producing the multilayered PPTC element are described next.

The PPTC core material 1 adopted by the utility model has positive temperature coefficient effect, and is specifically formed by blending crystalline polymer materials, an interfacial compatilizer, conductive fillers and auxiliary fillers.

The crystalline polymer material accounts for 10% -85% of the volume fraction of the conductive composite material base layer, for example, 10%, 47% or 85% of the volume fraction is selected. The crystalline polymer material is selected from one or more of polyethylene, polyvinyl chloride, polystyrene, polycarbonate, polyvinyl fluoride, maleic anhydride grafted polyethylene, polypropylene, polyvinylidene fluoride, ethylene-vinyl acetate copolymer, polymethyl methacrylate and ethylene-acrylic acid copolymer.

The conductive filler is selected from one or a mixture of two or more of carbon black, carbon nano tube, carbon fiber, metal powder or conductive ceramic powder, the volume resistivity of the conductive filler is lower than 200 mu omega cm, the particle size is smaller than 30 mu m, and more preferably the particle size is not larger than 20 mu m. The average particle diameter of the carbon black is 20nm-120nm; the particle size of the metal powder is 0.1-20 um, and the metal powder is one or more selected from nickel powder, copper powder and silver powder; the particle size of the conductive ceramic powder is 0.1um-50um, and the conductive ceramic powder is oxygen-free conductive ceramic powder and is one or more selected from titanium carbide, tungsten carbide, zirconium carbide, vanadium carbide, titanium boride and titanium nitride.

The interfacial compatilizer is a maleic anhydride grafted olefin polymer, and is specifically selected from one of maleic anhydride grafted high-density polyethylene, maleic anhydride grafted low-density polyethylene and maleic anhydride grafted linear low-density polyethylene.

The auxiliary filler is one or more selected from calcium oxide, zinc oxide, magnesium oxide, aluminum oxide, silicon dioxide, calcium carbonate, magnesium hydroxide and aluminum hydroxide.

The PPTC core material 1 may be prepared by a method described in the prior art (for example, a method disclosed in chinese patent CN102522173B, CN104319042 a), or may be prepared by the following method:

weighing the crystalline polymer, the interfacial compatilizer, the conductive filler and the auxiliary filler according to a certain mass ratio, and then mixing and granulating by using a proper mixing device such as an internal mixer, a double-screw extruder or a reciprocating single-screw extruder to obtain a PPTC compound;

the PPTC compound is added into a single screw extrusion calender set, and the PPTC core material 1 with the thickness of 0.05mm-2.0mm and the width of 1mm-150mm is prepared by a calendering mode.

The preparation method of the composite unit in the utility model is as follows (the parts related to the structure refer to fig. 2 to 4):

The PPTC core material 1 is prepared by adopting the method or the prior art;

and respectively compounding electrode foils on the upper surface and the lower surface of the PPTC core material 1 to form a first electrode layer 2 and a second electrode layer 3, and then carrying out irradiation crosslinking through electron beams or cobalt 60, wherein the irradiation dose is 1Mrads to 100Mrads, so as to obtain the compound unit.

In a specific embodiment, the electrode foil is a metal foil or a metal alloy foil.

In one embodiment, the electrode foil is copper foil, or nickel plated copper foil. The nickel-plated copper foil is formed by plating a layer of nickel on the roughened surface or both surfaces of the copper foil; the roughened surface is the surface attached to the PPTC core material 1.

In a specific embodiment, the preparation method of the composite unit comprises the following steps:

1) Weighing high density polyethylene (HDPE, HD5502FA, density 0.955 g/cm) 60.5% by mass ³ Shanghai Saike petrochemical Co., ltd.), 2.5% maleic acid shortbread Grafted polyethylene (Grafted-PE, fusabond E100, dow chemical), 37.0% carbon black (VVC 72, cabot), and then extruding and granulating by a twin screw extruder to obtain a PPTC compound;

2) Adding the PPTC compound into a single-screw extrusion calender unit, and preparing a PPTC core material 1 with the thickness of 0.5mm and the width of 10mm in a calendering mode;

3) Copper foils with corresponding sizes are compounded on the upper surface and the lower surface of the PPTC core material 1 according to specific structural requirements to form a first electrode layer 2 and a second electrode layer 3;

4) And (3) carrying out irradiation crosslinking on the structure formed in the step (3) through electron beams, wherein the irradiation dose is 50Mrads, and obtaining the composite unit.

The preparation method of the multi-layer PPTC element made by a plurality of composite units in the present utility model is as follows (see fig. 5 to 24 for structural parts):

the composite unit is prepared by adopting the method, and according to the structural design of the multi-layer PPTC element, insulating materials are coated on the inner side of the epitaxial electrode to be subjected to bending treatment to form an insulating part; further according to the structural design, the partial electrode layers laminated by the two composite units are connected by welding and/or are adhered by an insulating part formed by coating insulating materials; and further bending the epitaxial electrode to form a first electrode connection face or faces 41, and then cutting according to a desired size (which may be achieved by any one of punching using a punch, water jet cutting and cutter cutting), thereby preparing the multi-layered PPTC element. The soldering means include, but are not limited to soldering with solder paste 9.

In one embodiment, as shown in fig. 5 to 9, when the multi-layered PPTC element is two stacked base composite units 20, an insulating material is coated on the outer side of a first composite portion 21 where the two base composite units 20 are stacked, an insulating material is coated on the inner side of a portion where the first epitaxial electrode 22 of the lower base composite unit 20 is bent and/or the second side 14 of the upper base composite unit 20, and an insulating material is coated on the inner side of a portion where the first epitaxial electrode 22 of the upper base composite unit 20 is bent and/or the second side 14 of the lower base composite unit 20 to form insulating portions (61, 62). The stacked portion of the first epitaxial electrode 22 of the lower base composite unit 20 and the second composite portion 31 of the upper base composite unit 20 and/or the stacked portion of the first epitaxial electrode 22 of the upper base composite unit 20 and the second composite portion 31 of the lower base composite unit 20 are soldered by solder paste.

In a specific embodiment, as shown in fig. 10, when the multi-layered PPTC element is two stacked base composite units 20, insulating materials are coated on the outer sides of the first composite portions 21 where the two base composite units 20 are stacked, insulating materials are coated on the whole inner sides where the first epitaxial electrodes 22 of the lower base composite units 20 are bent and/or the second side surfaces 14 of the upper base composite units 20, and insulating materials are coated on the whole inner sides where the first epitaxial electrodes 22 of the upper base composite units 20 are bent and/or the second side surfaces 14 of the lower base composite units 20 to form insulating portions (61, 62).

In a specific embodiment, as shown in fig. 11 to fig. 14, when the multi-layer PPTC element is two stacked base composite units 20, the first composite portion 21 of the upper base composite unit 20 and the second composite portion 31 of the lower base composite unit 20 are welded by solder paste, and the number of welding positions is at least 2; insulating parts (62) are formed by coating insulating materials on the inner side of the bent part of the first epitaxial electrode 22 of the lower-layer basic composite unit 20 and/or the first side surface 13 of the lower-layer basic composite unit 20 and the second side surface 14 of the upper-layer basic composite unit 20; insulating portions (62, 63) are formed by coating insulating materials on the whole inner side of the bent first epitaxial electrode 22 of the upper base composite unit 20 and/or on the second side surface 14 of the lower base composite unit 20 and the outer surface of the first composite portion 21. And when the first epitaxial electrode 22 of the lower base composite unit 20 is laminated with the second composite portion 31 of the upper base composite unit 20 according to structural design requirements, the laminated portion is soldered by solder paste.

In a specific embodiment, as shown in fig. 15 to fig. 18, when the multi-layer PPTC element is a three laminated base composite units and the laminated manner is an upper base composite unit 30, a middle base composite unit 10 and a lower base composite unit 30, the outer surface between the second composite portion 31 of the upper base composite unit 30 and the second composite portion 31 of the middle base composite unit 10 is welded by solder paste, and the number of welded portions is at least 2; the outer surfaces between the first composite portion 21 of the middle-layer foundation composite unit 10 and the first composite portion 21 of the lower-layer foundation composite unit 30 are soldered by solder paste, and the number of soldered portions is at least 2. The first epitaxial electrode 22 of the middle basic composite unit 10 is partially or entirely coated with an insulating material, and the first side 13 of the middle basic composite unit 10 and the first side 13 of the upper basic composite unit 30 on the same side thereof can be coated with an insulating material to form an insulating part (62) according to requirements; the second epitaxial electrode 32 of the middle basic composite unit 10 is partially or entirely coated with an insulating material at the inside thereof, and the second side 14 of the middle basic composite unit 10 and the second side 14 of the lower basic composite unit 30 at the same side thereof may be coated with an insulating material to form an insulating part (62) as required. The laminated portion of the first epitaxial electrode 22 of the middle-layer foundation composite unit 10 and the first composite portion 21 of the upper-layer foundation composite unit 30 and/or the laminated portion of the second epitaxial electrode 32 of the middle-layer foundation composite unit 10 and the second composite portion 31 of the lower-layer foundation composite unit 30 are soldered by solder paste.

In a specific embodiment, as shown in fig. 19, when the multi-layer PPTC element is a laminated three basic composite units and the laminated manner is an upper basic composite unit 20, a middle basic composite unit 20 and a lower basic composite unit 30, the outer surfaces between the first composite portion 21 of the upper basic composite unit 20 and the second composite portion 31 of the middle basic composite unit 20 are welded by solder paste, and the number of welded positions is at least 2; the outer surface between the first composite portion 21 of the middle-layer foundation composite unit 20 and the first composite portion 21 of the lower-layer foundation composite unit 30 is soldered by solder paste, and the number of soldered portions is at least 2. The first epitaxial electrode 22 of the middle basic composite unit 20 is partially or completely coated with insulating material at the inner side, and the first side 13 of the middle basic composite unit 20 and the second side 14 of the upper basic composite unit 20 at the same side can be coated with insulating material to form an insulating part (62) according to requirements; the first epitaxial electrode 22 of the upper base composite unit 20 is partially or entirely coated with an insulating material on the inside thereof, and the second side 14 of the middle base composite unit 20 and the second side 14 of the lower base composite unit 30 on the same side thereof may be coated with an insulating material to form an insulating portion (62) as required. The laminated portion of the first epitaxial electrode 22 of the middle-layer foundation composite unit 20 and the second composite portion 21 of the upper-layer foundation composite unit 20 and/or the laminated portion of the first epitaxial electrode 22 of the upper-layer foundation composite unit 20 and the second composite portion 31 of the lower-layer foundation composite unit 30 are soldered by solder paste.

In a specific embodiment, as shown in fig. 20 to 24, when the multi-layer PPTC element is a stack of five stacked basic composite units and the stack is an upper basic composite unit 20, a first intermediate basic composite unit 20, a second intermediate basic composite unit 10, a third intermediate basic composite unit 20, and a lower basic composite unit 20, the outer surfaces of electrode layer portions stacked in two adjacent basic composite units are welded by solder paste according to the same concept as the preparation method of the three stacked composite units, and the number of welding positions is at least 2; insulating parts (62) are formed by coating insulating materials on the bending inner sides of the epitaxial electrodes to be bent and the side lamination parts of the basic composite units, and the epitaxial electrodes and the outer electrodes of the outermost basic composite units are welded through solder paste when being laminated. The specific parts and methods of coating the insulating material and the welding sites and methods are referred to in the preparation of the aforementioned multi-layered insert PPTC element formed based on the plurality of basic rechecking units 10, and will not be described herein.

In a specific embodiment, the PPTC core materials 1 of the multiple composite units may be PPTC core materials 1 prepared by the same formulation and having the same thickness, PPTC core materials 1 prepared by different formulations and having the same thickness, or PPTC core materials 1 prepared by different formulations and having different thicknesses.

The composite unit and the bi-layer, tri-layer and five-layer PPTC elements are further illustrated in conjunction with fig. 5-24, based on the above general description.

Example 1

As will be understood with reference to fig. 2. In the first composite unit 10 provided in this embodiment, the first electrode layer 2 protrudes from the first side 13 of the PPTC core material 1 to form the first epitaxial electrode 22, and the second electrode layer 3 protrudes from the second side 14 of the PPTC core material 1 to form the second epitaxial electrode 32, where the second side 14 and the first side 13 are disposed opposite to each other.

In this embodiment, the end of the first electrode layer 2 opposite to the first epi electrode 22 is flush with the PPTC core material 1, and in other embodiments, the end of the first electrode layer 2 opposite to the first epi electrode 22 may be slightly narrower than the PPTC core material 1.

Of course, the edge positions of the first electrode layer 2 except the first epitaxial electrode 22 may be set flush with the PPTC core material 1 or slightly narrower than the edge of the PPTC core material 1.

In this embodiment, the end of the second electrode layer 3 corresponding to the first side 13 is flush with the PPTC core material 1, and in other embodiments, the position of the second electrode layer 3 may be slightly narrower than the PPTC core material 1.

Of course, the edge positions of the second electrode layer 3 other than the second epitaxial electrode 32 may be set flush with the PPTC core material 1 or slightly narrower than the edge of the PPTC core material 1.

Example 2

As will be understood with reference to fig. 3. The second composite unit 20 provided in this embodiment differs from that provided in embodiment 1 in that: the second composite unit 20 of the present embodiment does not include the second epitaxial electrode 32. In order to more clearly embody the technical solution of the present embodiment, the following details are described with reference to fig. 3.

In the second composite unit 20 provided in this embodiment, the first electrode layer 2 protrudes from the first side 13 of the PPTC core material 1 to form the first epitaxial electrode 22, and the end of the first electrode layer 2 opposite to the first epitaxial electrode 22 is flush with the PPTC core material 1. Of course, the edge positions of the first electrode layer 2 except the first epitaxial electrode 22 may be set flush with the PPTC core material 1 or slightly narrower than the edge of the PPTC core material 1.

In this embodiment, the end of the second electrode layer 3 on the same side as the first epitaxial electrode 22 is flush with the PPTC core material 1, and the end opposite to the first epitaxial electrode 22 is also flush with the PPTC core material 1, and in other embodiments, these two positions of the second electrode layer 3 may be slightly narrower than the PPTC core material 1. Of course, the entire periphery of the second electrode layer 3 may be disposed flush with the PPTC core material 1 or slightly narrower than the edge of the PPTC core material 1.

Example 3

As understood with reference to fig. 4. In the third composite unit 30 provided in this embodiment, the first electrode layer 2 is flush with the periphery of the PPTC core material 1 or slightly adduced with respect to the PPTC core material 1, and it is apparent that the first electrode layer 2 does not have an epitaxial electrode extending out of the first side 13 and the second side 14. Likewise, the second electrode layer 3 is flush with the periphery of the PPTC core material 1 or slightly adducting with respect to the PPTC core material 1, it being apparent that the second electrode layer 3 does not have an epitaxial electrode extending beyond the first side 13 and the second side 14.

Example 4

As understood with reference to fig. 5. The double-layer PPTC element provided in this embodiment has a main structure made of two second composite units 20, and accordingly, the second composite units 20 are stacked to generate two first epitaxial electrodes 22 on opposite sides.

The two first electrode layers 2 having the first epitaxial electrodes 22 are bonded between the two PPTC cores 1 through the first insulating portion 61. One of the first epitaxial electrodes 22 is bent upwards along the side surface of the PPTC core material 1, a second insulating part 62 is arranged between the first epitaxial electrode 22 and the side surface of the PPTC core material 1, then the first epitaxial electrode is further bent and welded and fixed with the second electrode layer 3 at the first surface or surface group 51 through solder paste 9, the first epitaxial electrode and the second epitaxial electrode are corresponding to the first electrode connecting surface or surface group 41 together, and the part, which is not covered by the epitaxial electrode, of the second electrode layer 3 at the first surface or surface group 51 is the first electrode connecting surface or surface group 41. The other first epitaxial electrode 22 is bent downwards along the side surface of the PPTC core material 1 and a second insulating part 62 is arranged between the other first epitaxial electrode and the side surface of the PPTC core material 1, then the other first epitaxial electrode is further bent and welded and fixed with the second electrode layer 3 at the second surface 52 through solder paste 9, the other first epitaxial electrode and the second electrode correspond to the second electrode connecting surface or the second electrode group 42 together, and a part, which is not covered by the epitaxial electrode, of the second electrode layer 3 at the second surface 52 is the second electrode connecting surface or the second electrode group 42.

The first electrode member 71 and the second electrode member 72 are each sheet-shaped electrodes, and as shown in fig. 6, the left side of the first electrode member 71 is adjacent to or bonded to the outermost layer of the epitaxial electrode, and a first protruding portion 73 is formed at the right side position, and the right side of the second electrode member 72 is adjacent to or bonded to the outermost layer of the epitaxial electrode, and a second protruding portion 74 is formed at the left side position, thereby forming a double-layer band-shaped PPTC element. An encapsulating structure can be further arranged, the surface is wrapped by insulating materials, and only the two protruding parts are exposed.

Example 5

As understood with reference to fig. 7. The double-layer PPTC element provided in this embodiment has a main structure made of two second composite units 20, and accordingly, the second composite units 20 are stacked to generate two first epitaxial electrodes 22 on opposite sides.

The two first electrode layers 2 having the first epitaxial electrodes 22 are bonded between the two PPTC cores 1 through the first insulating portion 61. One of the first epitaxial electrodes 22 is bent upwards along the side surface of the PPTC core material 1, a second insulating part 62 is arranged between the first epitaxial electrode 22 and the side surface of the PPTC core material 1, then the first epitaxial electrode is further bent and welded and fixed with the second electrode layer 3 at the first surface or surface group 51 through solder paste 9, the first epitaxial electrode and the second epitaxial electrode are corresponding to the first electrode connecting surface or surface group 41 together, and the part, which is not covered by the epitaxial electrode, of the second electrode layer 3 at the first surface or surface group 51 is the first electrode connecting surface or surface group 41. The other first epitaxial electrode 22 is bent downwards along the side surface of the PPTC core material 1, and a second insulating part 62 is arranged between the other first epitaxial electrode 22 and the side surface of the PPTC core material 1, the end surface of the first epitaxial electrode 22 is flush with the surface of the second electrode layer 3 positioned on the second surface 52, the surface of the second electrode layer 3 positioned on the second surface 52 forms a first area 43, the end surface of the first epitaxial electrode 22 forms a second area 44, and the two end surfaces together form a second electrode connecting surface or a surface group 42.

The first electrode member 71 and the second electrode member 72 may be respectively provided with leads, and the first electrode member 71 and the second electrode member 72 are respectively protruded at right positions as shown in fig. 7 to form a first protruded portion 73 and a second protruded portion 74, thereby forming a dual-layer plug-in PPTC element.

In another embodiment, as shown in fig. 8, an encapsulating structure 8 is further provided on the basis of embodiment 5, and the surface is wrapped with an insulating material, exposing only two protruding portions.

Example 6

As understood with reference to fig. 9. This embodiment provides a dual layer PPTC element differing from embodiment 5 in the form of the electrode members and their relationship to the main body structure, and in particular, the first electrode member 71 and the second electrode member 72 employ sheet electrodes with the first protrusion 73 and the second protrusion 74 being located on opposite sides of the main body structure. The other parts of this other embodiment are the same as those of embodiment 5, thereby forming a double layer tape-shaped PPTC core material 1.

Example 7

As understood with reference to fig. 10. The present embodiment provides a dual-layer PPTC element, which differs from embodiment 5 in the form of the first electrode connection face or face group 41, the form of the electrode members and their relationship to the main structure, specifically, the first epitaxial electrode 22 is bent upward to be flush with the surface of the electrode layer located on the first face or face group 51 so that its outermost layer forms the second region 44, the electrode layer located on the first face or face group 51 forms the first region 43, the first electrode member 71 and the second electrode member 72 adopt sheet-like electrodes, and the peripheral edges of both are aligned with the side face of the main structure. The remainder of this other embodiment is the same as that of embodiment 5, thereby forming a double-ended PPTC element.

Example 8

As understood with reference to fig. 11. The double-layer PPTC element provided in this embodiment has a main structure made of two second composite units 20, and accordingly, the second composite units 20 are stacked to generate two first epitaxial electrodes 22 on opposite sides.

After the lamination, two first electrode layers 2 with first epitaxial electrodes 22 are respectively positioned at the second surface 52 and between the two PPTC core materials 1, the first epitaxial electrodes 22 positioned at the second surface 52 are firstly bent upwards along the side surfaces of the PPTC core materials 1, a second insulating part 62 is arranged between the first epitaxial electrodes and the side surfaces of the PPTC core materials 1, then the first epitaxial electrodes and the second electrode layers 3 positioned at the first surface or the surface group 51 are further bent and welded and fixed through solder paste 9, and the uncovered parts of the second electrode layers 3 positioned at the first surface or the surface group 51 form a first electrode connecting surface or a surface group 41. The first epitaxial electrode 22 between the two PPTC core materials 1 is bent downward along the side surface of the PPTC core material 1, a second insulating portion 62 is disposed between the first epitaxial electrode and the side surface of the PPTC core material 1, then the first composite portion 21 at the second surface 52 is further bent and completely covered, and a third insulating portion 63 is disposed between the first composite portion 21 for electrical isolation, and a second electrode connection surface or surface group 42 is formed by using the epitaxial electrode.

In this embodiment, the first electrode member 71 and the second electrode member 72 may be sheet electrodes, as shown in fig. 12, and two protruding portions with opposite protruding directions are formed after the main body structure is connected, thereby forming a double-layered band-shaped PPTC element. The present embodiment may further be provided with an encapsulation structure 8.

In another embodiment, the difference from embodiment 8 is in the electrode member and its relationship with the main body structure, specifically, the first electrode member 71 and the second electrode member 72 employ leads, and as shown in fig. 13, two protrusions having the same extending direction are formed after connecting the main body structure; the remainder of this alternative embodiment is the same as that of embodiment 8, thereby forming a dual layer plug-in PPTC element.

In another embodiment, the difference from embodiment 8 is in the form of the electrode connection faces or face groups and the relationship of the electrode members to the body structure: the second region 44 is formed by bending the first epitaxial electrode 22 located on the second surface 52 toward the first surface or the surface group 51, the first region 43 is formed on the surface of the second electrode layer 3 located on the first surface or the surface group 51, the first electrode member 71 and the second electrode member 72 are sheet-like electrodes, and the peripheral edges of the two sheet-like electrodes are aligned with the side surfaces of the main body structure after mounting as shown in fig. 14, and the other parts of this other embodiment are the same as those of embodiment 8, thereby forming a double-layer terminal PPTC element.

Example 9

As understood with reference to fig. 15. The three-layer PPTC element provided in this embodiment is made of a first composite unit 10 and two third composite units 30, the first composite unit 10 is located between the two third composite units 30, and the adjacent composite units are welded and fixed by solder paste 9.

After the three composite units are stacked, the first electrode layer 2 is located at the lower layer of the composite units, and the second electrode layer 3 is located at the upper layer of the first composite unit 10, obviously, the first epitaxial electrode 22 is relatively closer to the second surface 52, and the second epitaxial electrode 32 is relatively closer to the first surface or the surface group 51.

The first epitaxial electrode 22 is bent upward from a position close to the second face 52, is isolated from the side faces of the two PPTC core materials 1 by the second insulating part 62, and is then further bent to be welded and fixed with the first electrode layer 2 at the first face or the face group 51 by the solder paste 9. The second epitaxial electrode 32 is bent downward from a position close to the first face or face group 51, is isolated from the side faces of the two PPTC core materials 1 by a second insulating portion 62, and is then further bent to be welded and fixed with the second electrode layer 3 at the second face 52 by solder paste 9.

In this embodiment, the first electrode member 71 and the second electrode member 72 are sheet electrodes, and as shown in fig. 16, after the two electrodes are connected to the main structure, the first protruding portion 73 and the second protruding portion 74 are formed on opposite sides of the main structure, thereby forming a three-layer ribbon-shaped PPTC element.

In another embodiment, the difference from embodiment 9 is in the form of the electrode connection surface or surface group, the form of the electrode member, and the relationship between the electrode member and the main structure, specifically, the second region 44 is formed after the first epitaxial electrode 22 is bent, the first region 43 is formed on the surface of the electrode layer of the first surface or surface group 51, the first electrode member 71 and the second electrode member 72 are lead wires, as shown in fig. 17, the first protruding portion 73 and the second protruding portion 74 are formed on the same side of the main structure after the mounting, and the other portions of the other embodiment are the same as embodiment 9, thereby forming the three-layer insert type PPTC element.

In another embodiment, the difference from embodiment 9 is the form of the electrode connection surface or surface group, the form of the electrode member, and the relationship between the electrode member and the main structure, specifically, the first electrode connection surface or surface group 41 and the second electrode connection surface or surface group 42 are discontinuous surfaces composed of a plurality of surfaces, the first epitaxial electrode 22 is bent to form a second region 44, the surface of the electrode layer of the first surface or surface group 51 is formed into a first region 43, the second epitaxial electrode 32 is bent to form another second region 44, and the surface of the electrode layer of the second surface 52 is formed into another first region 43; the first electrode member 71 and the second electrode member 72 are sheet-like electrodes, and as shown in fig. 18, the peripheral edges of the first electrode member 71 and the second electrode member 72 are aligned with the side surfaces of the main body structure, respectively, after mounting, thereby forming a three-layer terminal-type PPTC element.

Example 10

As understood with reference to fig. 19. The three-layer PPTC element provided by the embodiment is characterized in that a main body structure is made of a second composite unit 20, a second composite unit 20 and a third composite unit 30 which are sequentially arranged, and adjacent composite units are welded and fixed through solder paste 9.

After the three composite units are stacked, one of the first epitaxial electrodes 22 is bent upwards, a second insulating part 62 is arranged between the first epitaxial electrode 22 and the side surface of the PPTC core material 1, and then the first epitaxial electrode is further bent and fixed with an electrode layer at the first surface or surface group 51 through solder paste 9, and an uncovered part of the electrode layer of the first surface or surface group 51 forms a first electrode connecting surface or surface group 41; the other first epitaxial electrode 22 is bent downwards, a second insulating part 62 is arranged between the first epitaxial electrode 22 and the side surface of the PPTC core material 1, then the second epitaxial electrode is further bent and fixed with the electrode layer at the second surface 52 through the solder paste 9, and an uncovered part of the electrode layer at the second surface 52 forms a second electrode connecting surface or surface group 42.

In this embodiment, the first electrode member and the second electrode member are sheet electrodes, and after the first electrode member and the second electrode member are connected to the main body structure, the first protruding portion and the second protruding portion formed are located at opposite sides of the main body structure, thereby forming a three-layer ribbon PPTC element.

In another embodiment, the difference from embodiment 10 is in the form of the electrode connection surface or surface group, the form of the electrode member, and the relationship between the electrode member and the main body structure, specifically, the second region is formed after the first epitaxial electrode is bent, the first region is formed on the surface of the electrode layer of the first surface or surface group, the first electrode member and the second electrode member are lead wires, the first protruding portion and the second protruding portion are formed on the same side of the main body structure after the first electrode member and the second electrode member are mounted, and the other portions of the other embodiment are the same as embodiment 9, thereby forming the three-layer plug-in type PPTC element.

In another embodiment, the difference from embodiment 10 is in the form of the electrode connection surface or surface group, the form of the electrode member, and the relationship between the electrode member and the main structure, specifically, the first electrode connection surface or surface group and the second electrode connection surface or surface group are discontinuous surfaces composed of a plurality of surfaces, the first epitaxial electrode is bent to form a second region, the surface of the electrode layer of the first surface or surface group forms a first region, the second epitaxial electrode is bent to form another second region, and the surface of the electrode layer of the second surface forms another first region; the first electrode member 71 and the second electrode member are sheet-like electrodes, and after being mounted, the peripheral edges of the first electrode member and the second electrode member are aligned with the side surfaces of the main body structure, respectively, thereby forming a three-layer terminal PPTC element.

Example 11

As will be understood with reference to fig. 20. The five-layer PPTC element provided in this embodiment, from the first surface or surface group 51 to the second surface 52, the composite units respectively adopt a second composite unit 20, a first composite unit 10, a second composite unit 20 and a second composite unit 20; electrode layers between adjacent PPTC core materials 1 are welded and fixed; after each composite unit is stacked, the first side 53 and the second side 54 have three epitaxial electrodes, respectively. And in the three epitaxial electrodes on the same side, the electrode layers corresponding to the two epitaxial electrodes are positioned between the two PPTC core materials 1, the two epitaxial electrodes are bent towards opposite directions, and the other epitaxial electrode is bent from a position close to one end of the multi-layer PPTC element and partially covers the electrode layer positioned at the other end of the multi-layer PPTC element.

As shown in fig. 21, the first electrode member 71 and the second electrode member 72 employ sheet electrodes, and the first protruding portion 73 and the second protruding portion 74 formed after both are mounted to the main structure are located on opposite sides of the main structure, thereby forming the five-layer ribbon-shaped PPTC core material 1. The present embodiment may further be provided with an encapsulation structure 8.

In another embodiment, the difference from embodiment 11 is in the form of the electrode connection surface or surface group, the form of the electrode member, and the relationship between the electrode member and the main structure, specifically, the second region 44 is formed after the epitaxial electrode on the first side 53 is bent, the first region 43 is formed on the surface of the electrode layer of the first surface or surface group 51, the first electrode member 71 and the second electrode member 72 are wires, as shown in fig. 22, two protruding portions are formed on the same side of the main structure after mounting, and the other portions of this other embodiment are the same as embodiment 11, thereby forming a five-layer plug-in PPTC element.

In another embodiment, the difference from embodiment 11 is in the form of the electrode connection surface or surface group, the form of the electrode member, and the relationship between the electrode member and the main structure, specifically, the first electrode connection surface or surface group 41 and the second electrode connection surface or surface group 42 respectively adopt discontinuous surfaces composed of a plurality of surfaces, two upwardly bent epitaxial electrodes on the first side 53 form the second region 44, the surface of the electrode layer on the first surface or surface group 51 forms one first region 43, the first region 43 and the second region 44 form the first connection surface together, and likewise, two downwardly bent epitaxial electrodes on the second side 54 form the second region 44, the surface of the electrode layer on the second surface 52 forms one first region 43, and the first region 43 and the second region 44 form the second connection surface together; the first electrode member 71 and the second electrode member 72 are sheet-like electrodes, and as shown in fig. 23, the peripheral edges of the first electrode member 71 and the second electrode member 72 are aligned with the side surfaces of the main body structure, respectively, after mounting, thereby forming a five-layer terminal PPTC element.

Example 12

As understood with reference to fig. 24. The five-layer PPTC element provided in this embodiment is different from embodiment 11 in that the second composite unit from the first surface or surface group 51 in this embodiment employs the third composite unit 30, and accordingly, after each composite unit is stacked, the first side 53 has two electrically connected epitaxial electrodes, one of which is bent downward, and the other of which is bent upward and is welded and fixed with the electrode layer at the first surface or surface group 51 by solder paste 9. Other portions of this embodiment are the same as those of embodiment 11, and will not be described here again.

As can be seen from the technical information, the multi-layer PPTC element provided by the utility model can be used for producing plug-in type, terminal type and strip type, and solves the problem that multi-layer plug-in type, multi-layer terminal type and multi-layer strip-shaped PPTC products cannot be produced in the prior art. Specifically, the multi-layer PPTC element is made of composite units, after each composite unit is stacked, the first side 53 and the second side 54 are provided with epitaxial electrodes, the epitaxial electrodes are processed to connect the PPTC cores 1 in parallel, a first electrode connection surface or surface group 41 and a second electrode connection surface or surface group 42 are formed, and the two electrode connection surfaces or surface groups can be matched with lead electrodes and sheet electrodes to form the multi-layer plug-in type PPTC element, the multi-layer terminal type PPTC element and the multi-layer strip-shaped PPTC element, and the manufacturing steps are simple and easy to operate.

It is emphasized that:

firstly, in the prior art, the production processes and production equipment of plug-in type PPTC elements, terminal type PPTC elements and strip-shaped PPTC elements are based on PPTC substrates, the PPTC substrates are always in a form of side flush due to mature production processes and production lines, the improvement of the PPTC substrates involves process adjustment and production line adjustment generated thereby, people are habitually produced according to the prior art, and the prior production processes, production lines and people's inertial thinking are limited, and no one has proposed to produce a multilayer structure by deforming the PPTC substrates; the utility model is based on a composite unit, at least two epitaxial electrodes are arranged in a plurality of composite units, and the parallel connection between PPTC core materials 1 is realized by bending the epitaxial electrodes and setting the relation between electrode layers, wherein the process for compositing the composite units with the epitaxial electrodes is different from the prior art, and each process involved in the lamination placement of each composite unit and the process for connecting each composite unit are also different from the prior art, in other words, the utility model breaks through the limitation of the traditional production process and breaks through the inertia thinking.

Second, the present utility model is a great commercial breakthrough. The multi-layer plug-in type PPTC element, the multi-layer terminal type PPTC element and the multi-layer strip type PPTC element which are generated by the composite unit can be widely applied to battery industry, telecommunication and industrial equipment, automobile electronics and new energy automobiles, electronic industry, intelligent small household appliances, security equipment and computer equipment, so that the multi-layer plug-in type PPTC element and the multi-layer strip type PPTC element have huge commercial value.

Thirdly, by setting the formula and thickness relation of each PPTC core material 1, different holding currents and rated voltages can be obtained, and therefore products with different safety grades can be obtained.

It will be evident to those skilled in the art that the utility model is not limited to the details of the foregoing illustrative embodiments, and that the present utility model may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. A multi-layer PPTC element, wherein the element is fabricated on a plurality of composite units; the composite unit comprises a PPTC core material and electrode layers arranged on two surfaces of the PPTC core material, and when the electrode layers extend out of the PPTC core material, the extending part is an extension electrode;

2. The multi-layered PPTC element of claim 1, wherein two electrode layers between adjacent PPTC cores are secured by welding and electrically connected or bonded and electrically isolated by an insulating material.

3. The multi-layer PPTC element of claim 1, wherein at least a portion of said PPTC core material is laterally provided with an insulating material to be electrically isolated from said bent epitaxial electrode.

4. The multi-layer PPTC element of claim 1, wherein at least one of said electrode connection faces or faces is disposed in series, said series of electrode connection faces or faces being accomplished by any of:

5. The multi-layer PPTC element of claim 1, wherein at least one of said electrode connection faces or sets of faces comprises a first region and a second region disposed intermittently, wherein electrode connection faces or sets of faces are achieved by any of:

6. The multi-layered PPTC element of claim 1, wherein said multi-layered PPTC element is made from a plurality of second composite units, or from a first composite unit and a third composite unit together, or from a second composite unit and a third composite unit together, or from a first composite unit, a second composite unit and a third composite unit together;

7. The multi-layer PPTC element of claim 6, wherein said composite unit is two and wherein said second composite unit is employed, wherein:

8. The multi-layer PPTC element of claim 6 wherein said composite units are three, one of said first composite unit and two of said third composite unit, wherein:

9. The multi-layer PPTC element of claim 6, wherein from said first face or set of faces to said second face, said composite units are a second composite unit, a first composite unit, a second composite unit, and a second composite unit, respectively; electrode layers between adjacent PPTC core materials are welded and fixed;

10. The multi-layer PPTC element of claim 1, further comprising a first electrode member and a second electrode member;

11. The multi-layer PPTC element of claim 10, wherein said first electrode member and said second electrode member are each sheet-like, and wherein a peripheral edge of said first electrode member and a peripheral edge of said second electrode member do not extend beyond a side of said multi-layer PPTC element.

12. The multi-layered PPTC element of claim 10, wherein one side of said first electrode member extends with respect to each of said PPTC core materials to form a first extension and one side of said second electrode member extends with respect to each of said PPTC core materials to form a second extension.

13. The multi-layered PPTC element of claim 12, wherein said first electrode member and said second electrode member employ leads, said first extension and said second extension being on the same side.

14. The multi-layered PPTC element of claim 12, wherein said first electrode member and said second electrode member are electrode sheets, said first extension and said second extension being on opposite sides.

15. The multi-layer PPTC element of any one of claims 12 to 13, wherein a surface of said multi-layer PPTC element is wrapped with an encapsulation structure and said first and second protrusions extend out of said encapsulation structure.

16. The multi-layer PPTC element of any one of claims 1 to 14, wherein each of said PPTC core materials is of the same thickness or at least one PPTC core material is of a thickness different from the thickness of the other PPTC core materials;